


One Dream

by sagely_sea



Category: Voltron: Legendary Defender
Genre: Alpha Keith (Voltron), Alpha/Beta/Omega Dynamics, Alternate Universe - Canon Divergence, Bottom Shiro (Voltron), Keith (Voltron) was Raised by the Blade of Marmora, Knotting, M/M, Mating Bites, Mating Bond, Mating Cycles/In Heat, Omega Shiro (Voltron), Soulmates
Language: English
Status: Completed
Published: 2020-02-24
Updated: 2020-02-24
Packaged: 2021-02-19 14:48:15
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,425
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22879435
Author URL: https://archiveofourown.org/users/sagely_sea/pseuds/sagely_sea
Summary: Voltron invited the Blades of Marmora over to plan a joint operation and Kolivan brings along one of the newest blades with him. Keith is excited to be trusted with such an important task but the second he removes his mask and breathes in the air of the CastleShip he smells the most perfect scent. His mate.An Alpha always knows without question and without a doubt the second he scents his soulmate. Unfortunately, it also sends him into a rut and the Black Paladin, Shiro, into a heat.There’s nothing to be done other than let nature take its course.
Relationships: Keith/Shiro (Voltron)
Comments: 8
Kudos: 184





	One Dream

**Author's Note:**

> My third fic for Bottom!Shiro week 2020. The prompts I used from my bingo card were knotting, biting, scent, soul mates, first time
> 
> As a small warning, mpreg is possible in this world and there is talk of breeding but both Keith and Shiro are on forms of birth control so it's either just dirty talk or thoughts of the future and not something that actually happens in this story.

Keith surveyed the room and everyone in it from behind his Blade mask as Kolivan made their introductions. He gave a nod when his name was mentioned but most of his focus was on the paladins. The princess and the black paladin looked somewhat competent but looking at the other three, Keith was amazed that Zarkon hadn’t destroyed them and taken back the lions yet. 

He really hoped he wasn’t tasked with working with any of those three. He wouldn’t mind working with the Black Paladin, Shiro, though. He was handsome, and Keith was glad his mask hid his non-professional perusal of him. It was unfortunate that he was probably an alpha, that size and that leadership type confidence just oozed alpha. Keith could work with other alphas just fine, especially once they learned that he could lift them up and body slam them despite his size, but dating an alpha was just out. It was too bad. Though maybe he was lucky and the man would be a beta.

Keith was brought out of his inappropriate ponderings by a gentle nudge from Antok as Kolivan moved closer to the table they were making plans at. As Kolivan brought down his mask, Keith decided he should, too. But as soon as he did, the most amazing scent hit him. It smelled like the fire his dad had made when he took him camping, the wood, the smoke, the dropped marshmallow sweetness as it caught fire. He licked his lips as he looked around, his eyes narrowing in on Shiro as the source of the scent. 

Oh. So he wasn’t an alpha at all but an omega. A large omega for a small alpha. Keith thought the fates may have been toying with him but he also wasn’t going to turn down their gift. Already his mind was chanting _mine_. 

An alpha always knew. Without hesitation, question, or doubt, when a mature omega was theirs at first scent. 

As Keith felt his body respond to his omega, he spared one last thought for poor Kolivan’s meeting and the horrible timing of this. But it was too late to deny nature and Keith wouldn’t be denied either. 

A growl escaped him as he saw the scrawny male paladin touch his omega. The only reason he didn’t attack was because he was still aware enough to notice it was out of concern and not with an intent to harm or flirt. 

“Hey, Shiro, are you okay? You’re not looking that great?” The bigger paladin, Keith thought his name was Hunk, asked. 

“He’s burning up. Sudden fever? Can that happen? Should we get him in the pod?” The one daring to touch his omega asked. 

“Oh no. I don’t think it’s a fever. You know that Galra have secondary genders just like you, right… well it seems…” Keith didn’t hear whatever else Coran was rambling on about. He was too busy prowling toward his omega as he rounded the table. 

“Alpha?” Shiro asked, looking confused and relieved by his presence. 

“My name’s Keith,” He said, his voice already low and rumbling from the start of his rut. 

“Keith… that’s not very Galra. You don’t look very Galra,” Shiro said. He reached out to touch Keith’s face and they both gasped at the first contact between them. 

“Half. I’m half human. Shiro…” He didn’t know what to say. It was so sudden. Most alphas never found their soulmate, and to find them while so young was a miracle. That it was the middle of a war and horrible timing for the black paladin to be out of commission wouldn’t take away from that for him. 

“Keith,” Shiro repeated as he stared into Keith’s eyes. It seemed like Keith wasn’t the only one who didn’t know how to proceed from here. 

“Uhhh should we pull them apart? This is a really bad time for this to happen,” The annoying one’s voice filtered through Keith’s haze. He turned a heated glare at him and felt smug at the surprised noise before the other hid behind Hunk. 

“It’s too late for that. Separating a soul bound pair at this stage would only lead to more pain. We should leave them so they can see things through to their natural conclusion,” Kolivan said. Keith liked the sound of the others getting far away from his omega. 

“They’re going to do that here?” A young voice said before making a gag sound. 

“I have a room,” Shiro said. 

Keith felt a shiver go through him at his mate’s voice and he nodded. He would have preferred to bring Shiro to his room, surround him with his alpha scent and spoil him but his room was galaxies away. Shiro’s room would be filled with familiar and comforting scents and things for Shiro and Keith knew he would enjoy being surrounded by his omega’s scent. Not his first choice but a close second and somewhere he wanted to be already. 

“Show me,” He commanded. 

It was Shiro’s turn to shiver and after a moment where Keith wasn’t sure if they would actually ever get out of the room or he’d be claiming his mate over the console, Shiro grabbed his hand and pulled him out of the room. There was no backward glance or acknowledging of the calls from the others, they were both too focused on each other and what their bodies needed. 

-0-0-0-0-0-

Shiro locked the door behind them as they entered his room and then he immediately started fussing with everything around the minimalist space. He wished he had more blankets and more things that showed off who he was to his alpha. As he fluffed a pillow, he knew it was his instincts and sudden heat making him act like this but he couldn’t help it. 

He honestly didn’t want to. Every unmated omega dreamed of finding their fated mate. They knew it would be a whirlwind but were told to embrace it, let go and trust that the universe knew what it was doing. He looked over at the alpha, Keith, who was prowling around the room and checking everything out. 

Keith wouldn’t have been his first choice of alpha but there was something appealing about the way he moved around with the grace of a lethal predator and those amazing eyes. And really, he was a single omega with plenty of failed dates behind him, maybe he didn’t know what he liked and needed the universe to help him out. 

Keith was slowly infusing his space with the scent of green tea and spring and now that they were away from the others and their various scents he found himself calming a little. His heat was still building, causing some discomfort at how suddenly it had hit him, but for the moment, the fog had lifted enough for him to appreciate just what the universe had gifted to him, even if the timing was awkward. 

“I’m sorry, I don’t have much,” Shiro said as he finally stopped fluffing the pillow and put it back on the bed. 

“It’s fine. More space for my things when I move in,” Keith said. 

Shiro hadn’t thought that far ahead, too focused on the now and their mating to think about what came after. “Right… Do you have a lot of things?” Shiro knew they’d have to talk more about their situation and how Keith would perform his Blade duties if he was here but that could come later. 

“Sort of. But not much that I need to take with me.” 

Shiro nodded and then swallowed thickly as Keith took off his blade and set it on a shelf. 

“I really want to get to know you more, Shiro, but…” He trailed off, fingers toying with something on his skin tight suit that Shiro assumed would help him get it off. It wasn’t as if the suit left much to the imagination but Shiro really wanted to see him out of it. See all of his alpha for the first time. 

“Same,” He said. He wanted to know everything about this mysterious half-human galra who was his mate but right now he wanted to be knotted and claimed more. 

He unzipped his vest and let it fall to the ground. He could clean up later. Much later. 

“Wow. You’re built. I thought you were an alpha when I saw you,” Keith said. He reached out a hand to touch one of Shiro’s pecs through his shirt and Shiro let out a shaky breath. 

“Most people do… sorry I’m not very omega.” 

“No! I wanted you to be an omega or at least a beta. I thought you were hot…. But I don’t get along with other alphas that way…” Keith’s cheeks were a rosy colour but his eyes were filled with determination as he spoke. 

“Thank you.” Shiro felt himself grow even warmer at the compliment and knowing his alpha wanted him. Maybe he hadn’t been initially drawn to the little Blade until his scent had hit him but now he couldn’t wait to see what the handsome man could do to him in bed. 

“I’m the one who should apologize. I know even by Earth standards I’m not huge. But I swear I’m strong and skilled and I can protect you… not that I think the leader of Voltron needs much help. But I can have your back,” Keith said. 

Shiro gave a wavering smile and nodded, overcome with emotions. His alpha was perfect. Maybe he was a little rough around the edges but he was fierce and protective but clearly respectful. Shiro had met plenty of alphas who thought that since he was an omega he needed coddling or couldn’t keep up with the alpha pilots. Even after they saw his records they still acted like that. It was ridiculous. But then here comes this alpha from space who knows exactly what to do and say somehow. 

“I believe you. And if my size doesn’t bother you then your size doesn’t bother me,” Shiro said. 

He then shifted his weight from foot to foot as he felt his slick drip from his hole. From the way that Keith took a deep breath as his eyes grew large before focusing, he knew that his arousal had been scented. 

“I don’t think I can talk anymore. I need you,” Keith said. 

“I need you, too,” Shiro said. He could feel his body really heating up now. 

It had been ages since he’d had a heat and normally it was a slow build over days and just a short time was spent in the depths of a haze-filled need to mate but he’d gone from nothing to desperate in less than an hour and he didn’t think he could ignore it anymore. Whatever reprieve the privacy of his room had given them was rapidly ending.

It seemed like Keith was of the same opinion because in a flurry of limbs and clothes, they were naked and touching and Shiro was in heaven. When was the last time he had spent a heat with anyone? When did someone’s touch make him feel like this? 

He couldn’t remember the first but he knew the second was never. Even the gentle caresses of exploration were sending the type of tingles through his body he normally only got when someone was stroking his cock. 

“Need you in me. Need your knot, alpha,” Shiro said. He was losing himself to his heat but this time there was no fear or worries. He knew his alpha would take care of all of his needs and see him safely to the end. 

“I got you, Shiro. I’ll give you what you need.” 

Shiro felt the world tip over and found himself lying on the bed, his alpha kneeling over him before kissing whatever sense he had left right out of him. 

-0-0-0-0-

Keith couldn’t believe his luck. This strong, fierce, warrior, was an omega and all his. Every scar was a testimony to his strength and will to survive and Keith vowed to kiss each and every one of them when they both had more patience. 

After attempting to devour him through kisses, Keith dragged his mouth to Shiro’s neck, scenting and licking first one side and then another. When he found Shiro’s scent gland, already swelling from his sudden heat, Keith couldn’t help but worry it with his teeth in a gentle warning of what he’d do later. 

How could one man smell and taste so perfect? Like one of Keith’s best memories come to life to both soothe him and make him so desperate. He took one last deep breath of Shiro’s neck and then kissed and bit his way down his chest, tugging on his nipples before going lower. 

For an omega, Shiro had an impressive cock and Keith took a moment to lick the length of it and nibble on the tip before nosing his way under it to deeply inhale at his balls. There was a male muskiness here but still that campfire of burning cedar and toasted marshmallows. Keith could lose himself in that scent but he needed more. 

He slid his hands under Shiro’s knees and pushed them out and up to lift Shiro’s ass higher into the air and give him more room to work with. There it was. Leaking, tight, and oh so perfect. Keith licked his lips before diving in to lick and suck at Shiro’s hole. 

Shiro moaned and writhed under his hold so Keith held him tighter and nipped at the inside of his thigh when Shiro started to get too restless. “Behave. I got you,” Keith said, his voice rough with want but commanding. 

To an omega in heat, there was no way he could resist his voice and he felt Shiro relax under him before keening in need. Keith wasn’t likely to get anything too coherent out of Shiro until he was knotted and sated but that was fine. He didn’t think he could be that coherent either. He was only holding it together as much as he was because his omega needed him. 

It was their first time and they were going to bond. He needed to make this feel good and he do this properly. 

Keith worked at Shiro’s hole until his jaw started to ache and even then he worked his tongue in a bit more, trying to get more of that delicious slick Shiro was producing in amazing amounts. His mate was so powerful and so fertile. Keith knew in the back of his head that they were both likely on some form of birth control but in the midst of his rut, all he could think of was how well Shiro would take him and his seed. 

“You ready for me?” Keith asked as he straightened. He wiped his face with the back of his hand before leaning down to kiss Shiro. He was dazed and flushed and making the most needy and beautiful noises that Keith had ever heard. 

As he kissed, he rocked his cock against Shiro’s ass and knew with just a little pressure and the right angle it would be so easy to slip right into his loosened and wet hole. He could fuck him into the mattress and watch his face as he clung to him and came around his knot. At just the thought he growled and thrust a bit harder against Shiro making them both gasp. 

It was so tempting and he was so impatient but if he wanted to bond with Shiro, he needed access to the back of his neck. Biting at Shiro’s bottom lip one more time, Keith finally pulled back and smirked as Shiro whined and reached out to him. 

“Nooo, alpha. I need you. Don’t go,” He said. 

Keith wondered if Shiro got annoyed at how needy and vulnerable he was during his heat or if the strong leader of Voltron embraced the moments where he could let go and trust someone else to take care of him. 

Something to explore in the future. Right now, Keith needed in his ass. “Turn over,” He said. 

Shiro was so eager to do so that he nearly kicked Keith in the groin in the process but quick reflexes saved him. He helped Shiro get comfortable, and then pressed in tight behind him, his hands running over Shiro’s fine muscled ass in circles before grabbing them and seeing how much they’d jiggle. They were firm, but there was still enough plumpness to get a good handful. 

Keith didn’t know what was wrong with other alphas to not see how perfect Shiro was. But that was probably why Shiro was his fated mate and not theirs. “Going to breed you so good, Shiro. Fill you up and plug you with my knot,” Keith said. He usually wasn’t one for dirty talk but he couldn’t help it. He needed Shiro to know he was his and just what he’d do to him. And by the way Shiro writhed under him and moaned, he didn’t think Shiro had any complaints. 

He rubbed his cock between Shiro’s perfect cheeks, teasing them both with what was to come but not giving it to them. When he couldn’t take it anymore he gripped one of Shiro’s cheeks and guided the head of his cock to Shiro’s hole. It was as if time stood still for a moment before he pushed in the same time Shiro rocked back. 

He had meant to take it slow but with both of them moving in synch he slid right inside of Shiro to the hilt. They both groaned and Keith had to grip Shiro’s hips hard to stop him from moving. It felt so good with Shiro’s tight wet walls massaging him that if he didn’t take a moment he’d pop his knot right away.

“Fuck. You feel so good, Shiro,” Keith said as he moved his hands up and down Shiro’s back, pushing down on his shoulders to make him lean down and rest his head on his arms. 

“Mmm you, too,” Shiro said. He was relaxed under Keith for the moment, clearly in bliss from being so perfectly filled. But Keith knew it wouldn’t last since Shiro hadn’t got what he really needed yet, a good hard pounding and a knot, but he was happy to take advantage and trail kisses over Shiro’s shoulders and neck, teasing him with little bites. 

When Keith was sure he could move without knotting, he straightened and started rocking his hips, slowly at first and then harder as Shiro encouraged him for more. Skin was slapping against skin as he hammered into Shiro, holding on tight to his hips to keep him from sliding up the bed. 

The sounds coming from Shiro made him burn as he let out a mix of moans, pleading, and the type of warbles of pleasure that were only heard from an omega who was in pure bliss from an alpha cock. 

“Gonna come on my knot, Shiro?” Keith asked. 

“Yes. Need your knot… so close,” Shiro managed to say between gasps of air and moans. 

“Want my bite? My mark?” Keith asked, his own voice sounding breathless and low. 

“God yes. Bite me and fill me.” 

Keith didn’t need anymore encouragement than that. He slid his arms under Shiro’s arm pits and lifted, pulling him up away from the bed and against his chest. He teased one of Shiro’s nipples before sliding his hand down to stroke Shiro’s cock. 

“Get ready,” He warned against Shiro’s skin. He gave a few more hard thrusts, finding it harder to move as his knot began swelling and finally thrust in hard just as his knot grew too big to move. He ground up into Shiro as he bit hard into his neck, drawing blood and bonding them for life. 

He held on tight as Shiro squirmed and moaned his way through his orgasm, set off either by his knot, his bite, or both. The way Shiro’s hole massaged his knot was enough to set off Keith’s own orgasm and he shot his heavy load deep into Shiro. 

He moaned against his neck, teeth still firmly embedded as he continued to release his seed in what had to be the strongest and longest orgasm he’d ever had. 

It seemed like hours and not nearly long enough when he started to come to his senses again. He slowly drew back his teeth and licked at the marks. The magic of a true mating mark meant it was already healing by the time he pulled his mouth away. Though it would also leave a clear scar as a visible warning to others that this omega was his. 

He gave the mark a kiss and breathed in deep. They smelled of sex and each other and it soothed him to know he’d claimed his mate so well. 

“You okay?” He asked as he finally let go of Shiro’s softening cock. 

“Mmmhmm,” Shiro more hummed than said. He was leaning most of his weight back against Keith and while not uncomfortable for now, Keith didn’t know how much longer his knot would last. He’d heard some alphas boast about it lasting over an hour the first time they knotted their mates but he wasn’t sure he believed that. 

“Going to move us, okay?” Keith clearly signalled how he was moving and with just a few tugs of his knot that made him gasp in pleasure and Shiro groan, he got them on their side so he was spooning Shiro close to him, their legs tangled. “Better?” 

“Yeah...Never taken a knot before,” He said. He still sounded dazed but there was more a sated sleepy quality to it than the desperate need from before. 

“Really? I thought it was the best thing for your heat.” It was why Shiro was so languid now. A good solid knotting was the best way to calm down an omega in heat. At least as far as Keith knew. 

“Sex and toys but no knot... wanted it to be special,” Shiro said, his words slurring a little. 

That sort of thinking was a little traditional but it was also sweet and Keith’s inner alpha was bursting with territorial pride at being the first to knot Shiro and breed him like this. “Thank you. It’s very special.” He stretched up so he could give Shiro’s mating bite a proper kiss.

It must have been sensitive because it caused Shiro to gasp and tighten around his knot which in turn caused Keith to gasp and try to thrust forward. “Fuck. You feel too good,” Keith said trying not to continue rocking into Shiro. His mate had been through a lot and they both needed rest. He didn’t know if just the one knotting would be enough to get them through their rut and heat and wanted to be ready in case they needed a second round. 

“You, too. I feel so full.” Shiro brough Keith’s hand to his stomach. 

While it still felt muscled and smooth to Keith he rubbed his hand in a circle and joined Shiro in a hormone fuelled mating instinct to picture what it would be like to breed Shiro properly. Maybe after the war. Maybe making and raising kids with Shiro would be enough to keep him out of trouble. 

He laughed lightly at the thought. All of his numerous self-appointed uncles in the Blades would say nothing could keep him out of trouble. But then he’d never had a mate before. 

“What’s funny?” Shiro asked, his head turning to look over at Keith. 

“Nothing. Just having strange thoughts of the future and if you might be able to keep me out of trouble.” 

Shiro snorted and reached back to pull Keith into a kiss. “I’m more likely to join you in trouble. Sorry.” 

Keith certainly wasn’t sorry about that. Everything he knew about Shiro was how professional he was and what a good leader he proved himself to be. It was nice to know that his mate would match him outside of the bedroom, too. 

“I think trouble is more fun. Speaking of, you’re going to have to show me what you do around here for fun when you’re not saving the universe,” Keith said. 

“Mostly train,” Shiro said and then paused. “Are you going to be around a lot?” 

“Just try to get rid of me, mate.” 

It was the right thing to say as Shiro pulled him back in for another kiss. “I thought you’d still do Blade work but we’ll find something for you to do. There’s plenty of missions we do outside of the Lions and Coran is always looking for more help in the ship,” Shiro said. 

“I can’t wait.” And while Keith would miss the work he did with the Blades, he would find a way to be useful to his mate and make sure he and his team survived this war. 

“I’ll show you around later.” 

“Much later. We need rest,” Keith said. 

Shiro hummed in agreement, the burst of energy he had seeming to have gone as quickly as it came. He got comfortable on the pillow and then snuggled back against Keith. And just when he thought Shiro had nodded off, he felt the amazing and purposeful squeeze of muscles around his knot. 

Keith moaned and ground against Shiro’s ass on instinct. “Brat. Behave.” 

“Yes, alpha,” Was the quiet response into the pillow. 

Keith waited to see if he’d be squeezed again or if Shiro would think of something else to say. But once he was sure that Shiro was asleep for real this time, his breathing soft and even, he let himself relax.

His mate was safe, sated, and properly bonded to him. It was okay to sleep. Later, they could work out how they’d fit into each other’s lives and likely drive everyone crazy with their inability to stop touching. But Keith was looking forward to the honeymoon phase of boding and wasn’t going to try to act like anything but a proud and smitten alpha. The others would just have to deal. 

He was excited to show off his mate to the others and also eager to fuck Shiro and knot him again and the sooner he slept the sooner he could do those. He forced himself to relax, cuddled in close to his mate, amazed at how natural it felt, and let his eyes close. 

-end-

**Author's Note:**

> I'm proud I managed to keep that under 5000 words. I challenged myself to get to the sex as quickly as I could and I think I did a pretty good job with it. I also meant for this to be a bit dirtier and a smidge dubcon as they were totally taken over by instincts but my Sheith muses still insist on some tenderness so it ended up a bit softer than expected. 
> 
> As always, comments and kudos are appreciated. You can also swing by my twitter [@SagelySea ](https://twitter.com/SagelySea)


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